It is known in the art to provide a projector which modulates light emitted from a light source unit by using a spatial light modulator and which projects the modulated light in an enlarged form onto a screen through a projection optical system such as a projection lens, etc. Traditionally, a metal halide lamp or a halogen lamp has been used as the light source unit for such a projector. However, in recent years, for such purposes as downsizing the light source unit and the projector while at the same time achieving extended service life and enhanced image quality, a display apparatus has been proposed that uses a light source constructed from laser diodes (LDs) of three primary colors (RGB) (for example, refer to patent document 1).
The laser light source used in the projection-type display apparatus disclosed in patent document 1 has a can-type structural stem. More specifically, an LD chip is rigidly fastened onto a common terminal that is connected to the stem by vertically passing therethrough, and the common terminal and a terminal to which the other electrode of the LD chip is connected by a wire are brought out to the back side of the stem; then a cylindrically shaped metal cap having a transparent window is mounted on the stem to seal the LD chip therein. In patent document 1, a laser unit which includes three such can-type laser light sources, one for each of the RGB colors, and which combines the laser light from the respective laser light sources by using a plurality of dichroic mirrors and outputs the combined laser light through a lens, is proposed as the light source for the display apparatus.